New Study Finds Dogs Can Smell Cancer In Blood With 97% Accuracy

Published: July 19, 2019

A recent study has discovered that canine scent can be used in detecting cancer. According to the BioScentDx, four trained dogs have been able to sniff out blood samples of patients with lung cancer with 97% accuracy. This discovery paves new ways into understanding cancer, it's early detection and treatment.

It is a well-known fact that dogs have a much stronger sense of smell than humans. It’s no wonder that they like to sniff around so much. Science shows that dogs have smell receptors that are 10,000 times more accurate than the ones that we have.

Scientists have tried to use this powerful ability of dogs in curing cancer. Since canines sense odors that we humans can’t even perceive, they tried to see if there is a way that dogs can recognize blood samples of people affected with cancer by using their sense of smell.

When they conducted multiple tests with trained dogs, it turned out that dogs could pick out blood samples from people with cancer with almost 97 percent accuracy. If you wonder what are the benefits of this discovery, the answer lies in its cost-efficiency and the lack of invasiveness for the human body.

Who Was The Study Performed By?

The study was performed by a group of researches from BioScentDx, a company whose mission is to use canine scent detection to create a non-invasive way of screening for cancer and other life-threatening diseases. They are developing affordable and scalable testing of the early detection of cancer. When cancer is recognized at an early stage, chances of survival are much higher and treating cancer in this stage offers the best opportunity for eradicating this disease.

The team that performed the study was lead by Mrs. Heather Junqueira, the lead researcher at BioScentDx. Before working with BioScentDx, Junqueira had experience in breeding and training dogs and worked as a breed manager at Southeastern Guide Dogs. She also had experience in training dogs that could monitor diabetes while working for a non-profit. That’s where her passion for changing human lives for the better by training dogs to become even better companions to their owners came to life.

How Was The Study Performed?

The first step in preparing the study was to train four dogs to perform the task of smelling out the blood samples and picking the ones from patients with malignant lung cancer. All four dogs were Beagles since they are considered to be among the dog breeds that have the most sensitive sense of smell. Junqueira and her colleagues applied a form of clicker training in order to teach these dogs to perform this task.

Although one dog, called Snuggles, didn’t really enjoy participating and didn’t perform at all, the other three dogs showed incredible results that few people could have hoped for. They correctly identified blood samples of lung cancer patients 96.7 percent of the time, while they identified normal blood samples with a 97.5 accuracy.

How Can This Discovery Help In Detecting Cancer?

According to Junqueira, the outcome of their study is very exciting because it paves the way for further research on new cancer-detection tools. More precisely, the discovery opens two paths for researchers. “One is using canine scent detection as a screening method for cancers, and the other would be to determine the biologic compounds the dogs detect and then design cancer-screening tests based on those compounds.”

Screening has inevitably shown good accuracy in detecting cancer, but sometimes it could also lead to other problems such as overtreatment. Or, the screening test might show that there is cancer when there actually isn’t one. Although these flaws in accuracy are very rare, it is still a way too stressful thing to be gambled upon. Also, in many countries screening is quite an expensive detection tool, and on the other side, the exposure to the x-rays can worsen some types of cancer, making it a slightly invasive detection method.

On the other hand, the new discovery of Junqueira and her team from BioScentDx could be used for the development of a new, non-invasive way of detecting cancer, and other life-threatening diseases. In order to perfect this method, the company will launch a breast cancer study in November this year. This time, their plan is to see if dogs can sniff cancer out of the samples of participant’s breath, instead of the blood sample.

Another idea they are intending to do is to find which chemical components help dogs identify cancer. By isolating these substances that cause the odor thanks to which dogs manage to detect the disease, they would pave a way to understand much more about cancer, it’s treatment and the way it is detected.

Canine Sense Of Smell

Canines learn about the world around them with their senses. They have the same senses as we do, but some of them are much more powerful than ours. And one of those is the sense of smell. This is why dogs tend to smell everything first, even new dogs they meet, new people they meet, their food, toys and so on.

To show you how powerful a dog’s sense of smell is, check out these facts that BioScentDx shared on their website:

Dogs have 300 million smell receptors. (Humans have only 5 million)

Dogs smell receptors are 10,000 more sensitive and accurate than ours.

A dog could detect a spray of perfume in a small stadium.

A dog could detect a half teaspoon of sugar in an olympic-size swimming pool.

Dogs can smell minute changes in hormones, proteins and other organic compounds in humans.

Thanks to their highly evolved sense of smell, dogs have been trained to aid in monitoring conditions such as diabetes, narcolepsy, and cancer. Previous studies have shown that dogs can detect cancer from human breath, fecal, and urine samples with 99% accuracy. BioScentDx is trying to replicate those studies and prove that similar results can be achieved.

Dog Scent Used For Other Medical Aids

As we already mentioned, this is not the first time dog scent is used to help with diseases in humans. There are trained assist dogs that help people with type I diabetes lead lives of higher quality. These dogs can smell specific scent in the human breath that is linked to dropping or very low blood sugar levels. After that, they are trained to alert the person with diabetes by pawing or nudging them.

The person should then check his or her blood sugar level. The way these dogs are trained is actually very similar to the process of training drug sniffing in police dogs.